On Wed, Oct 08, 2003 at 12:23:04 +0100, Harry Broomhall <[EMAIL PROTECTED]> wrote: > I wonder if anybody could give me a few pointers on a problem I face. > > I need to do an UPDATE on table A, from an effective left outer join > on A and another table B. (This is trying to perform a number translation, > where the items that need it are rare.) > > The following points *I think* are relevant: > > 1) The FROM clause in UPDATE should *only* show additional tables, > otherwise I'll get an extra join I didn't want! (IMHO this could do > with being emphasised in the docs.)
But that might be the best approach. If you do a left join of A with B in the where clause and then an inner join of that result with A you should get what you want. If the optimizer does a good job, it may not even be much of a hit to do that. ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
